Surface finishing machine



May 9, 195o A. P. ROBINSON 2,507,052

SURFACE FINISHING MACHINE Filed June 13, 1947 3 Sheets-Sheet l @L 7.9/6/gf-fl /m/EN T012 H1. 55m l? Poe/fvwm firme/YE y.:

N O S m B o R R A SURFACE FINISHING MACHINE 3 Sheets-Sheet 2 Filed June13, 1947 May-9, 1950V A. P. ROBINSON 2,507,052

l SURFACE FINISHING MACHINE Filed June 13, .1947 K 3 Sheets-Sheet 3Patented May 9, 1950 UNITED STATES est' GFFICE SURFACE FINSI-IING AlbertP; Robinson, SeattlmWash.

Applica-tion Jnell'S, 1947, Serial'No. '754,366A

(Cl. 50i-417) It is the principalY object` of this invent-ion` tofprovide means foruse with grinding apparatus.,` that makes a fasterandxoetter nishing opera-A tionpossible, without anydanger-of gouging,or marring a surface by reason of improper holding` of the grindingdisk', andfal'sorelievesthe opera-V tor of theheavy strain of holdingthe grindingf machine. in a dennite position for the specific Work beingdone.

Explanatory tothe invention,.it willy be. here: stated that in thenishing or surfacing of floors, baseboards, stairways, etc., of terrazzoorfthe like, itis usually the case that .a'revoluhly driven grinderofdisk-like form is employed. This: diskis fixed on the drive shaft of amotor, andthe motor housing is equipped with handles whereby' theoperator hold'sand guidesthe device inruse. To insure an even', smooth.surfacethat is free-oiy irregularities or disk marks', .itisnecessarythatthe# grinding disk be' held` perfectly .at againstthesurface `being nished; fork ifitfshould be tilted to onesidelortheother, it isquitexaptto lquickly cut-V an arcuatel groove that'.defrnagingl to the; surface'iand detrim'entalto itsfappearance;Furthermore, .the holding'of the grinder `inV the proper position by'hand is a strain on the operator and`r becomes quite exhausting.especially when machines of' large' size are" used.

In view ofithe foregoing. explanatory matter. itha's'been one ofthe-principal objects ofrthisi inventionto provide a light; substantialframe structure, that maybe :easily skidded on thesuri: facebeingiinished or: adjacent thereto, and. in which the grinder may be placedand secured in proper position for the nishin'g of a surfacefth-usto'mechanically ho'ldthe grinder tofinsuren the desired evenness of thesurface'finish and valso torelieve Ythe :operator of the heavy strainofholding 4 the-machine against that' tiltingfor improper po sition that`would'result inA damage to .a surfacebeing .finished .Itis alsoy an.object of the inventiontoiprovidef' risers, base moldings, eta, orfonother Vuses;

Still another object of the invention istoi'pro-' vide a frame structurein which the grindingmachine may be adjustably secured for Woriron3floors, or other horizontal surfaces, and which frame may be turned onits side with grinder mounted therein, to support thev grinding-diskproperly for operation von Vertical sunfacespsuch`v as baseboards.;stair risers, and the like.

Still further objects of the invention residein" the .details ofconstruction and combination of parts embodiedinthe combination-ofgrinderandff frame, and inthe modeof usenand operatiorrasv will.hereinafter be described;

In accomplishing the above mentioned` and other objects: oi theinvention, I have.' provided the improved details of construction, thepref ferred Yforrns oi which are illustratedin theaccompanyingAdrawings, wherein- Fig. 1 isa-plan; or top view of Ya` surfaceiinishingmachine yembodied by the present invention.

Fig. 2 isla side viewof` the same showing the grinding'machine assupported in position for fmishin'g ancor surface.

Fig. Sis a forward endview of the grinder andl the supporting framestructure,` a-s positioned forl surfacinga baseboardor vertical surface.

Fig. 4 isa cross-section, taken on the 'line lle-4i supporting framestructure, showing the'adjust# ment ofthe grinding machine for a floorsandingv operation.

Fig.; 7 is an end View of the machine showing?l the position of thegrinder for a stair riser sur.-4 facingl operation.

Fig'. 8-isanfelevation of a machine oframodi.V`

ned for-In.

Referring :morein detail to the drawings-- First, it will .be explainedthat in the present? combination-i contemplate using motor drivengrinders like, or similar to, those noW- in general useforl doorsurfacing operations, and altering them only to the lextent necessary toadaptthem' for use inthe presentv supporting and. guidingframestructure. invention, that the means for supporting.y the grinderinfthevframe Ybe. oiV such. character;that.'A

the-latter may be easilyv and readily disposed in the .frame at anynecessary or advantageouspo@I sition. The-,function of the framestructure, Pri marifly, is to holdthe grinder. at such-level'opposi tionthat .theigrinding disk will natly engagelwithi the-'surface beingfinishedand not lallovifgedfto Also, it is theintent inl this' gouge in;however, it serves additionaly as a means of sustaining the weight ofthe grinder that is usually held by the operator. Furthermore, by reasonof the adjustability of the grinder in the frame, the grinding stone canbe held at any set position of inclination as required for any specicwork.

In the drawings, I have illustrated one common type of grinder,designated in its entirety by reference numeral ID, and it comprises anelectric motor within a motor housing of cylindrical form, designated atA gear case |2 is fixed rigidly to what will be referred to as the outerend of the motor, and a tubular portion I3 of reduced diameter, servingas a handle, extends from the inner end of the housing I I. Other handlemembers i4 and |5 are fixed rigidly to the parts and I2 for conveniencein the handling of the machine in use, especially when the grinder isused independently of the supporting frame structure.

Extended downwardly from the gear case l2, is a motor driven shaft I5and mounted on this is a grinding disk Il. This disk surface lies in aplane parallel to the longitudinal axis of the housing IU. As seen inFig. 1, the grinding disk is of such diameter that it extendssubstantial amounts to opposite sides of the housing i0 and alsoforwardly of the gear case I2.

The frame structure in which the grinder is supported for use, as notedbest in Figs. 1 and 2, comprises parallel, horizontally extending,opposite side shafts -2B, between which two cross rods 2| and 22, areextended; each of which cross rods is equipped at its opposite ends withfittings 23 that are longitudinally slidable on the shafts 2li-20. It isupon the cross rods 2| and 22 that the grinder is operatively supportedvfor use, as will presently be more fully described.

Secured rigidly to the opposite ends of the shafts 23 and 2E), arevertical, tubular members 25, each of which has a frame supporting leg2S adjustabiy contained therein. Each leg is in the form of a solid rodthat extends at its lower end from its containing tube E, and at thatend is equipped with a shoe or runner 2S of a type that is easy to slideor skid upon a floor surface. For purpose of vertical adjustment of thelegs 2E, the upper end portions of each of the tubular members 25 arelongitudinally split and equipped with clamp screws 29 adapted to betightened for the securernent of the legs at any position of adjustmentas may be required to properly engage the grinding stone of the grindersupported on the frame with a surface being worked on.

The upper end portions of the rods or legs 26 are equipped with rackteeth 3| formed therealong and cross shafts 32 are extended between legsat opposite sides of the frame and revolubly held at their ends inbearings 33 on the upper ends of corresponding tubes 25. These shaftsare equipped with gear pinions 34 at their ends in mesh with the rackteeth of the legs to provide for making simultaneous and equaladjustments A hand wheel 35 is fixed on each shaft for turning it inmaking an adjustment.

The grinding machine, comprising the motor, its housings E I and |3, thegear housing I2 and disk are designed to be handled as a unit, and to befunctionally mounted in the frame structure. The means of support forthe grinder comprises the two cross rods 2| and 22, which, as previouslystated, are adjustable along the opposite side shafts 2li-29 of theframe. It is shown best in Figs. 4 and 5, that bearing rings or bands 40and 4| are xed about the motor housing parts II and |3, near the forwardand rearward ends of the grinder and these bands have spherically curvedouter surfaces and are tted for turning in enclosing bearing bands 43and 44 that, respectively, are mounted upon the cross rods 2| and 22.

It is shown in Fig. 4, that the band 43 is equipped at its lower sidewith a longitudinally split bearing portion 43x that is mounted on thecross rod 2| for endwise shifting thereon, and this portion is equippedwith a clamp screw 45 for securing it at any set position. The band 43also is -cut at the top, as at 46, and a clamp bolt 41 joins the endsacross the joint for drawing the 'band tight to secure the motor againstmovement after a rotatable adjustment thereof has been made.

Likewise, it is shown in Fig. 5, that the spherically surfaced band 44which is fixed about the smaller end of the motor housing I3 isrotatably contained in a collar 44 that, at opposite sides has bearingportions 5I5| that are vertically adjustable on parallel, vertical posts52-52 fixed in a bearing member 53 that is mounted on cross rod 22 foradjustment transversely of the frame. This bearing has a clamp bolt 54associated therewith and adapted to be tightened to hold the bearing atany set position of adjustment.

It is to be understood that the described means of support for thegrinder permits it to be ro.- tatably adjusted on its longitudinal axisfor the lateral tilting of the grinding disk, and also permits theforward end of the motor to be swung laterally to either side of theframe, for example, to positions corresponding to the dotted lineposition shown in Fig. l. Furthermore, the mounting permits the up anddown adjustment of one end of the grinder, for example, as shown in Fig.6, as required for sanding a oor surface; a special sanding disk, offlexible character being used for this work.

The supporting frame structure, also, is equipped at opposite ends withupper and lower tubular cross rods and 6I xed at opposite ends to thevertical members 25. Adjustably mounted in the opposite ends of thesetubular members are gauging or guiding shoes 65, with at outer surfacesadapted to engage in sliding contact with a wall or floor to insureagainst the grinding disk being gouged into a wall surface. These shoes,also, are designed to serve as supports for the frame when it is turnedon its side for use as has been indicated in Fig. 3. The guide shoeshave mounting rcds of substantial length telescopically contained in thecross rods 60-6l and set screws 66 are applied to the cross rods fortightening against these rods for the securement of the shoes at any setposition of adjustment.

Assuming the parts to be so constructed and assembled, the use of thegrinder in this combination would be as follows:

First, the motor housing would be properly equipped with the bearingbands 40 and 4I, and the proper or a selected grinding disk Then thedevice is secured in the frame by seating the bands 40 and 4| in theirrespective bearing bands 43 and 44. The latter bands are then tightenedto rigidly secure the grinder in its frame and the legs 26 are adjustedvertically in the tubular guides 25 so that, by means of the frame. thegrinder is held secure and the surface of the disk I'I is located inproper grinding relationship e me fiar surface. with the we se .een Phegrinder is set in position, arid is ,in ly Skidded'back andfcrth on thefio'or ui'face'duif ing the lgrinding operation,` bei'rigf'heldpro ly inplace at all ltimes the frame in lieu. of having to be held by theoperator; Thus,V the chance of gouging and uneven grinding elimihated ayd' the'eort of collars and"4|',"which are secured to the motor housing,may turn freely inthe clamp rings because of their spherical outsideform. In this adjustment, the cross' rods 2l and 22 will automaticallyadjust themselves in spacing on their supporting shafts. Set .Screws 110.in the fittings 23 may be tightened against the shafts 520e-ezt! tosecureA the adjustment.

' It is indicated Aalso in Fig. 1, that thegrinder mightbe shiftedendwse so that :the disk might project forwardly of the frame, as to thedotted line'pcsition of the disk designated at Ilya Since it may, attimes, be advantageous to use the grinder independently of thesupporting frame structure, I have provided for its quick and easydetachment from the frame merely by the withdrawal of the cross shafts2l and 22 from their fittings 23. Ordinarily the cross rods are securedby cotter keys passed through their end portions as at 'l2 in Fig. 2.

With the grinder secured properly in the frame structure, it is possibleto manipulate it in the usual manner for any oor surfacing operation.The operator may grasp the framework or the handles of the housing forthe movement of the grinder on a floor. The advantage of its use withthe frame resides in the fact that it is impossible to tilt it to anyposition at which the grinder disk can damage the floor; even grindingis insured, and the heavy strain on the workman of holding the grinderin proper position is avoided.

If work is to be done close up to a baseboard, the grinder is firstadjusted to one side of the frame, as indicated by dotted lines in Fig.1, then the shoes 65 at that side are extended for guiding contact withthe side wall surface so as to eliminate possibility of gouging or thedisk cutting in too deep.

When it is desired to grind the face of a base-V board or other verticalsurface, the frame structure may be turned on its side, as in Fig. 3, sothat the shoes B5 at one side then become the frame supporting skids.The shoes or runners 28 may then be extended as wall contacting guides.Adjustments for properly positioning the grinding disk I1 are made aspreviously explained and operation for this job is substantially as forthe surfacing of a floor.

For the surfacing of undercut stair risers, the frame is laid on theside in the same manner as for baseboard grinding and the motor is thenrotatably adjusted about its longitudinal axis, as has been illustratedin Fig. 7, to bring the grinding surface of the disk I1 to a properdegree of inclination. Work is then carried on as for base surfacing.Also, by reason of the adjustability manually l h'lfding the' Eig 8illustrati-,esa modif-led or alternative Aform of devicewherein a`fratrie .structure substantialiy ted 'is employed. A motor l ss rodstlfor rotatable .adr vertical agis, and the'grindnig y i citarneiaradiaiiv directed arm 83 may be 'swung to advantgeus positions.

t in the useof machines be made whereby l,the oiaticaliy lifted clear. sutile' off of power. Such .a mechanism ,duld' be rmanually or' au oniacllv erated. y

Having thus'v described my invention, .what I' claim new therein,4 anddsire .to 'secure by Lettere Peten?, 1.S= m' 1: The .combiner face'iini'shin nachineoff portable .type 4 ing a liqusiiig, lar motor ven-shaft extended from the housing land a 4Ence xed ,tie-Sna ,tfif ,asiipilt 'guided-:Cor th'mchine ctznprising'r an' open 'frame structurefor the reception of the machine therein, means for the securement ofthe machine, in different working positions, in the said open framestructure, and surface engaging runners adjustably fixed on said framestructure and whereby the machine will be sustained while in functionaluse and the disk held in a definite relationship to the sustainingsurface; said means for securement of the machine comprising a band forencircling the said housing and adapted to be tightened thereabout, anda cross support in said open frame on which said band is fixed fortilting adjustment to change the working angle of the disk.

2. The combination with a power driven surface finishing machinecomprising a housing, a motor driven shaft extended downwardly from thehousing and a surface finishing disk fixed to the shaft, of a supportand guide for the machine comprising an open frame structure adapted toreceive the machine therein, and including means for the securement ofthe machine in working position therein, and runners mounted by theframe at opposite sides and ends of the machine, whereby the machinewill be sustained in working relationship to the supporting surface;said runners being adjustably mounted on the frame to maintain the diskin a working relationship to the surface being finished thereby; saidmeans for the securement of the machine in said open frame comprising across-support in said open frame, a band encircling the said housing andequipped to be tightened thereabout, and tiltably secured to the crosssupport, for angular adjustment of the machine, and a verticallyadjustable support for the machine fixed in the the housing and :asurface iinishing disk Xed to the shaft, of a support and guide for themachine comprising a, rectangular, open frame structure, adapted toreceive the machine therein and having corner posts and horizontal barsrigidly connecting said posts along opposite sides of the frame, crosssupports extended between opposite side bars, means for adjustably xingthe said machine thereon with its disk in working relationship to thesurface to be finished, runners mounted at the four corners oi the framefor sustaining the machine in use and adjustable to maintain the diskparallel to the surface and at a. designated working elevation.

f 4; A combination as recited in claim 3 wherein the said cross supportsare slidably adjustable along said horizontal bars to dispose thegrinding disk beyond or within the end of the said frame structure.

' 5. A combination as recited in claim 3 wherein the said cross supportsare slidably adjustable along said horizontal bars to dispose thegrinding disk beyond or within the end of the frame structure, andwherein said machine is angularly adjustable on said supports to locatethe disk at one or the other side of the said frame structure.

6. The combination with a power driven surface finishing machinecomprising a housing, a motor driven shaft extended therefrom and asurface nishing disk fixed to the shaft, of a support and guide for themachine comprising an open rectangular frame structure comprising cornerposts, horizontal rods connecting said posts atV sides and'ends of theframe, cross bars mounted on the horizontal rods at opposite sides andslidably adjustable therealong, means on said cross bars adjustablyfixing the said machine thereon in working position, and runners at the,lower ends of the posts to support the machine at proper working levelfor iioor surfacing operations, and other runners on the sides of theframe for guiding contact with a wall or for functional support of theframe and machine when laid on its side for baseboard surfacingoperations.

'7. A machine as recited in claim 6 wherein the said runners are adjustably mounted on the frame and said machine is rotatable in itsmountings to adapt the positions of the disk to different positions ofthe frame.

' j ALBERT P. ROBDISON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 48,062 Harsha June 6, 1865589,006 Manning Aug. 31, 1897 1,224,943 Lux May 8, 1917 1,340,991 TaborMay 25, 1920 1,772,636 Re Qua et al Aug. 12, 1930 1,799,109 Lyne May 31,1931 2,201,420 Zschan May 31, 1940

